Rotary mill



Ocf. 12 1926.

W. J. A. LONDON ROTARY MILL Filed Nov. 19,

1924 2 Sheeis-Sheet 1 A TTORNEYS Oct. 12 1926.

W. J. A. LONDON ROTARY MI LL Filed Nov. 19, 1924 2 Sheets-Sheet 2 %I&VEN R H v #zw ATTORNEYS Patented Oct. 12, 1926.

UNITED STATES 1,602,622 PATENT OFFICE.

WILLIAM J. A. LONDON, OF HARTFORD, CONNECTICUT, ASSIGNOR TO INTERNATIONAL COMBUSTION ENGINEERING CORPORATION, A CORPORATION OF DELAWARE,

ROTARY MILL.

Application filed November 18, 1924. Serial No. 750,753.

This invention relates to rotary pulveriz ing mills and particularly mills for pulverizing coal for powdered fuel burning appa ratus, and will therefore be described in connection therewith, but it has general application in mechanism such for example as employ rotors and stators where its principles may be put into effect for the removal and or replacement of working parts. It is therefore to be understood that the terms rotary mill and rotor as employed herein'are not used in a strictly limited sense.

Coal pulverizing mills such, for example, as illustrated and described in the co-pending application of John E. Bell and myself, Serial No. (384,950 filed January 8th, 19 24, are subject to heavy duty at high speeds. The wear and tear on certain parts is very great and this is particularly true of the impeller blades which must needs be renewed frequently. To do this conveniently involves removing heavy parts of the machinery, such, for instance, as the complete rotor for purposes of repair and replacement. This necessitates shutting down the mill, sometimes for a considerable period of time inconveniencing the power plant or, where there are several pulverizers, putting an additional burden on the others. Since mills of this type supply large installations it will be seen that shut-downs of the mill involve large losses through the consequent shut-down of the installatlon.

In the ordinary mill construction, to effeet heavy repairs to the rotor, or other wearing parts, it is necessary-to completely remove the top of the housing, or the casing lid, remove the bearin caps, and lift out the rotor, a heavy and awirward part toremove. and handle. It is likewise difficult and inconvenient, in replacing such parts,to line them up readily and-to handle them without damage or maladjustment to the machinery or injury to the workmen.

One of the main objects of myinvention is to make it possible to remove a worn part and replace it with a new or repaired part in a minimum of time and w th minimum labor, so that the period of time durin which the mill is out of action is corres n ingly short, whereby the operation of t e installation supplied by the mill. is not sub fitantiallyinterfered with, and may not be interfered with at all. .Similarly, if it is necessary to have another mill take up the burden of the mill out of action, the period of such heavy duty will be short.

Another object of my invention is to make inspection of the interior of the mill more easily accomplished without disturbing its moving parts.

Still another object of the invention is to make the handling of heavy and awkward parts of the machinery easier with less likelihood of injury to the workmen.

In general, I aim by my invention to improve the operation' of pulverizers and the power plants they supply, from the standpoint of economy of both time and labor in making repairs.

How the foregoing, together with such other advantages as will occur to those skilled in the art, are obtained will be clear from the following description of my invention, reference being had to the accompanying drawings, wherein ig. 1 is a broken-away side elevation of a pulverizing mill emb ying my improvements. 7 p

Fig. 2 1s a side elevation of the same mill but with the upper part of the casing in raised position, and showing the carrying rails of a repair truck inserted beneath the rotor.

Fig. 3 is another side elevation of the mill showing the rotor resting on the truck and installed.

Referring now particularly to Fig. 1, the

numeral 1 indicates the movable or lid portion of the mill housing, which is pivoted to the stationary part 2 at the hinge 3 and bolted thereto byv means of flanges 4, 5 and bolts 6. 'Therotor 7, of'the mill,has an axle 8 running in bearings 9, the lower part of each bearmg being mounted on a pedestal 1 0 and the upper part of the bearin being mounted in a bearing cap 11. Theie caps 11 are held in ace by nuts 12 on bolts 13 pivoted at 14. I'Peavy hook-like members 15 are pivoted on each side of the housing on lugs or projections 16 of sufficient length to allow the hooks, in swinging, to clear the flange 4L Normally, with the lid of the mill in closed sition, the hooks '15 are suprted at tli: free end by a button-like memr 17 orsome other suitable arrangement. Bearing cap lifting links 18- areprovided on aring each side of the housing, thesebeing pivotally connected to the bearing caps at 19 and slidably mounted on the projections 20 on the housing at the proper distance'to clear the hooks 15 and to give a substantially ver tical lift to the bearing caps when brought into play.

The drawings show other parts, usual to pulverizers and not part of my present invention, such as the fuel inlet 21 at the side of the mill, fuel discharge opening 22 at the bottom, and inspection man-hole 23 at the top.

The removal of a rotor is effected in this way: Bolts 6 are loosened. Bearing cap nuts 12 are loosened enough to allow the bolts 13 to be swung down to the position shown in Figures 2 and 3. The hook retainers 17 are removed. A crane hook or other lifting means 24: is inserted in the ring 25 and the lid 1 raised thereby. When the lid has been raised a little distance the pins 20 come up against the top of the links 18 (one being on each side of the housing). Raising the lid a little farther raises the links 18 and by them the bearing caps 11, at first with a nearly vertical lift, but as the motion continues swings them backward out of the way.

When the bearing caps have been raised about half their normal travel the hooks 15 come into play. They are swung down to engage the rotor axle 8 at approximately the time when their pivots 16 are in a hori- -zontal plane with the pivot 3 of the housing.. By virtue of their, position on the housing in relation to the housing pivot 3, the pivots 16 swing through a wider arc than the link supports 20, and consequently they lift the rotor forward a little from its bearings, thus allowing the carrying rails 26 of a truck 27 (see Fig. 2) to be readily inserted beneath the axle 8, one rail on each side of the. rotor disc. I

As shown in Figs. 2- and 3 the truck 27 is equipped with ,revoluble rollers 28, guide rails 29 to line up the truck with the mill, and a weight 30 to counterbalance the weight of the rotor 7 when it has been deposited by the hooks 15 on the end of the carrying rails 26. I

The rotor is readily deposited on the truck by dropping down the housing lid just a little and swinging the books 15 up out of the way The truck 27 bearing the worn rotor 7 is then moved away from the mill and up to a nearby' cradle 31, the stop-pins 32 and 33 are removed from the truck and cradle, and the rotor rolled onto the cradle to await repair.

A fresh or repaired rotor can then be installed, this being, of course, merely a reversal of the process just described. The

truck 27 is moved "to another cradle, ta es on the new rotor, and is pushed into its proper position at the mill. The hooks 15 are swung down to engage the axle 8. The crane lifts the lid 1 a little leaving the rotor suspended by the hooks. After the truck is removed the lid 1 is let down, dropping into place, first, the rotor 7, then the bearing caps 11, coming finally to rest, itself, in closed position. The hooks 15 are swung up out of the way, the bearing nuts and bolts 12 and 13 are tightened up, the flange bolts 6 are screwed down and the mill is once more ready for operation.

It will be noted that the mill housing is split at about a angle, which brings the pivot point near the top of the machine, which is of importance in making it possible to introduce the carrying rails into the machine forreception of the rotor to be removed and for the insertion of the replacement rotor. The location of the hinge is also of importance in securing straight lifts on both the bearing-caps and the rotor. By virtue of the lost motion between the pins 20 and the ends of the links 1.8 the bearingcaps' may be seated readily. This also makes it possible to partially open the lid for inspection without disturbing the remaining parts. The fact that the rotor is not lifted until the bearing-caps are out of the way has an additional advantage in that the lifting power is most effectively applied, and thrust on the hinge is avoided, practically the only load carried by the hinge being a proportion of the load of the parts being lifted.

It will be seen from the foregoing that a worn rotor can be removed and replaced by a new onein a minimum of time and with a minimum of labor, making the shut-down of the mill of such temporary character as not to involve shut-down of the installation beyond, perhaps, but a few moments at most.

I claim 1. The combination in a rotary mill of a divided casing, one member of which is movable with respect to the remainder and means associated with the movable member adapted to engage and carry the rotor of the mill free of its bearings when moved.

2. The combination in a rotary mill of a divided casing, one member of which is hinged, and means on the hinged member adapted to engage and carry the rotor of the mill from its bearings when moved on itshinge.

3. The combination in a rotary mill of a divided casing, one member of which is hinged at a point toone side of the vertical central plane of the mill, and means on the hinged member adapted to en age and carry the rotor of the mill free 0% its bearings when moved on its hinge.

4. The combination in a rotar mill of a divided casing, one member 0 which is Ill) ' housing adapted to raise the bearing1 hinged at a point between the vertical and horizontal central planes of the mill, and above said horizontal plane.

5. The combination 1n a rota mill of a divided casing, one member 0 which is hinged at a point between the vertical and horizontal central planes of the mill, and means on the bin ed member adapted to engage and carry t e rotor of the mill free of its bearings when moved on its hinge.

6. The combination with a rotary mill having a rotor, bearings for the rotor and a divided housing, of means for raising the bearing caps from the hearings on movement of one part of the housing.

7. The combination with a rota mill having a rotor, bearings, and a divide housing, of means for raising therotor free of its bearings on movement of one part of the h0l1Sl II1%.

8. e combination with a rotary mill havin a rotor, bearings fortthe rotor, and

a divided housing, of means for movin the bearing caps and lifting the rotor out o and into its bearings on movement of one part of the housing.

9. The combination with a rotary mill having a rotor, bearings for the rotor, and a divided housin of means for moving the bearing caps an the rotor in sequence on movement of one part of the housing.

10. In a rotary mill having a rotor and bearin for the rotor axle the combination of a divided housing, means attached to the caps, apted other means attached to the housing a I to raise the rotor from its bearings, both of said latter means actuated by movement of one member of the housing,

11. In a rotary mill having a rotor and bearin for the rotor axle the combination of a divided housing and means attached to the housin adapted to raise the bearing caps and t e rotor from its bearings in sequence, said means actuated by movement of one member of the housing.

12. The combination with a rotar mill havin a rotor, bearings, and a divide housing with one of its parts ivoted to the remainder at a point on t e periphery, of means adapted to raise the bearing caps, and

means adapted to lift out the rotor, both of said means actuated by' the movement of the pivoted part of the housing.'

13. In a rotary mill having a rotor and bearinssfor said rotor, the combination of a divi ed casing, .one member of which is pivoted to the remainder, means on the movable member adapted to-lift the bearing caps clear of the axle, other means on the movable member adapted tolift the rotor from its bearings to a height sufiicieht to permit the insertion of conveying means below the rotor axle, both of said lifting means actuated by the movable part of the casihg.

14. In a rota mill having a rotor and bearin s for sai rotor, the combination of ,a divi ed casing, one member of which is bearin s for sai rotor, the combination of a divi ed casing, one member of which is pivoted to the remainder, means on the movable member adapted to lift the bearing'caps clear of the axle, other means on the movable member adapted to lift the rotor from its hearings to a height sufficient to permit the insertion of conveyin means below the rotor axle, both of said' liftin means actuated by the movable part of t e casing, and each of said means coming into play only when its respective point of attachment to the casing has come to a point in its arc of motion substantially in a horizontal line througlh the pivot of the casing.

16. n a rotar mill having a rotor and bearings for said rotor, the combination of a divided casing, one member of which is pivoted to the remainder, means on the movable member adapted to lift the bearing caps clear of the axle, other means on the movable member adapted to lift the rotor from its bearings to a height sufficient to permit the insertion of conveying means below the rotor axle, both of said lifting means actuated in sequence by the movable part of the casing, and each of-said means coming into play only when its respective point of attac ment to the casing has come to a oint in its arc of motion substantially in a orizontal line through the pivot of the casing.- 17. In a rotary mill having a rotor and bearin s for said rotor, the combination of a divide casing, one member of which is pivoted to the remainder, means on the movable member adapted to lift the bearing caps upwardly and rearwardly clear of the ax e, other means on the movable member adapted to lift the rotor from its bearings upwardly and forwardly to a height suflicient to permit the insertion of conveyin means below the rotor axle, both of said 1i ing means actuated by the movable part of the casing.

18. In a rotary mill having a rotor and bearin s for said rotor, the combination of a divi ed casing, one member of which is pivoted to the remainder, means on the movable member adapted to lift the bearing caps upwardly and rearwardly clear of the ax e, other m ans on the movable member adapted to li the rotor from its bearings up-' wardly and forwardly to a height suflicient topermit the insertion of conveying means below the rotor axle, both of said lifting means actuated in sequence by the movable part of the casing.

19. In a rotary mill having a housing with a lower portion and a pivoted upper lid portion, a rotor, and bearings for the rotor, apparatus adapted to remove and install rotors comprising: links swung from each side of the housing lid, attached to the bearing caps and adapted to raise said caps when the lid is raised; and hooks, also swung from said lid, adapted to engage the axle of the rotor and lift it from its bearings when the lid is raised higher.

20. In a rotary mill having a housing with a lower portion and a pivoted upper lid portion, a rotor, and bearings for the rotor,

apparatus adapted to remove and install rotors comprising: links swung from each side of the housing lid, attached to the bearing caps and adapted to raise said caps when the lid is raised; and hooks, also swung from said lid, adapted to engage the axle of the rotor and lift it from its bearings when the lid is raised higher, said links and hooks being swung from the lid at a point or points on each side intermediate the pivot and lifting-point of the lid.

21. In a rotary mill having a rotor and bearings, the combination of a divided oasing, one member of which is hinged at a point above the horizontal central plane and to one side of the vertical central plane of the mill, and apparatus adapted to remove and install rotors comprising links swung from each side of the housing lid, attached to the bearing caps and adapted to raise said caps when the lid is raised; and hooks, also swung from said lid, adapted to engage the axle of the rotor and lift it from its bearings when the lid is raised higher.

22. In a rotary mill having a rotor and bearings, the combination of a divided casing, one member of which is hinged at a point above the horizontal central plane and to one side of the vertical central plane of the mill, and apparatus adapted to remove and install rotors comprising links swung from each side of the housing lid, attached to the bearing caps and adapted to raise said caps when the lid is raised; and hooks, also swung from said lid, adapted to engage the axle of the rotor and lift it from its bearings when the lid is raised higher, the link and hook'on either side being swung from a point or points lying approximately in the vertical centralplane of the mill when thelid is in closed position.

23. The method of removing worn parts of a mill having a divided casing, one part ofwhich casing is hinged to the remainder for movement with respect thereto, which consists in engaging the part to be removed with the movable part of the casing and in movingsuch part of the casing to disengage from the mill the part to be removed.

24. In combination a rotor, bearings therefor, a stator having a portion thereof movable, and means associated with the movable portion adapted to engage and carry the rotor free of its bearings when moved.

In testimony whereof, I have hereunto signed by name.

WILLIAM J. A. LONDON. 

